Theoretical and experimental demonstration of the relationship between microstructure and the DC-bias-superposition characteristic of ferrite materials

Highlights: • We proved how to improve DC-bias-superposition characteristic of ferrites. • We confirmed the correctness of the theoretical result by experiment. • This research provides a good guide for developing more stable ferrites. - Abstract: DC-bias superposition is important for ferrite materials used in power components. However, methods of improving this characteristic of ferrites have not yet been clearly established. In this study, we theoretically prove that a ferrite with high intrinsic permeability composition and thick grain-boundary microstructure provides better DC-bias superposition than a ferrite with low intrinsic-permeability composition and thin grain-boundary microstructure given the same permeability. We then validate the theoretical results by experiments. Results can guide the development of ferrite materials while considering permeability and stability for the improvement of DC-bias superposition.